Answer this question truthfully
### Question: What causes Relapsing fever?
### Response: Relapsing fever is an infection caused by several species of bacteria in the Borrelia family.
There are two major forms of relapsing fever:
Tick-borne relapsing fever (TBRF) is transmitted by the Ornithodoros tick and occurs in Africa, Spain, Saudi Arabia, Asia, and certain areas in the western United States and Canada. The bacteria species associated with TBRF are Borrelia duttoni, Borrelia hermsii, and Borrelia parkerii. Louse-borne relapsing fever (LBRF) is transmitted by body lice and is most common in Asia, Africa, and Central and South America. The bacteria species associated with LBRF is Borrelia recurrentis.
Sudden fever occurs within 2 weeks of infection. In LBRF, the fever usually lasts 3-6 days and is usually followed by a single, milder episode. In TRBF, multiple episodes of fever occur and each may last up to 3 days. Individuals may be free of fever for up to 2 weeks before it returns.
In both forms, the fever episode may end in "crisis." This consists of shaking chills, followed by intense sweating, falling body temperature, and low blood pressure. This stage may result in death in up to 10% of people.
After several cycles of fever, some people may develop dramatic central nervous system signs such as seizures, stupor, and coma. The Borrelia organism may also invade heart and liver tissues, causing inflammation of the heart muscle (myocarditis) and liver (hepatitis). Widespread bleeding and pneumonia are other complications.